Auto "cross" task lists with issue reference
Description
You can create task lists in issues, but you are not able to link the checkbox with another issue so its crossed when the linked issue is closed. This would make "master tickets" quite easy to maintain.
Proposal
If you use a link to another ticked in the checkbox eg * [#3123] the cross will be set on the state of the ticket gitlab-ce#3123 and the text shown will be the title of the ticket